[PATCH] execute-in-place fixes
[linux-3.10.git] / fs / ext2 / xip.c
index d44431d1a338cd24e3c054b789fc46b2c219a755..0aa5ac159c0940947925425c06d2a688c0bb05bc 100644 (file)
 #include "xip.h"
 
 static inline int
-__inode_direct_access(struct inode *inode, sector_t sector, unsigned long *data) {
+__inode_direct_access(struct inode *inode, sector_t sector,
+                     unsigned long *data)
+{
        BUG_ON(!inode->i_sb->s_bdev->bd_disk->fops->direct_access);
        return inode->i_sb->s_bdev->bd_disk->fops
                ->direct_access(inode->i_sb->s_bdev,sector,data);
 }
 
+static inline int
+__ext2_get_sector(struct inode *inode, sector_t offset, int create,
+                  sector_t *result)
+{
+       struct buffer_head tmp;
+       int rc;
+
+       memset(&tmp, 0, sizeof(struct buffer_head));
+       rc = ext2_get_block(inode, offset/ (PAGE_SIZE/512), &tmp,
+                           create);
+       *result = tmp.b_blocknr;
+
+       /* did we get a sparse block (hole in the file)? */
+       if (!(*result)) {
+               BUG_ON(create);
+               rc = -ENODATA;
+       }
+
+       return rc;
+}
+
 int
-ext2_clear_xip_target(struct inode *inode, int block) {
-       sector_t sector = block*(PAGE_SIZE/512);
+ext2_clear_xip_target(struct inode *inode, int block)
+{
+       sector_t sector = block * (PAGE_SIZE/512);
        unsigned long data;
        int rc;
 
        rc = __inode_direct_access(inode, sector, &data);
-       if (rc)
-               return rc;
-       clear_page((void*)data);
-       return 0;
+       if (!rc)
+               clear_page((void*)data);
+       return rc;
 }
 
 void ext2_xip_verify_sb(struct super_block *sb)
 {
        struct ext2_sb_info *sbi = EXT2_SB(sb);
 
-       if ((sbi->s_mount_opt & EXT2_MOUNT_XIP)) {
-               if ((sb->s_bdev == NULL) ||
-                       sb->s_bdev->bd_disk == NULL ||
-                       sb->s_bdev->bd_disk->fops == NULL ||
-                       sb->s_bdev->bd_disk->fops->direct_access == NULL) {
-                       sbi->s_mount_opt &= (~EXT2_MOUNT_XIP);
-                       ext2_warning(sb, __FUNCTION__,
-                               "ignoring xip option - not supported by bdev");
-               }
+       if ((sbi->s_mount_opt & EXT2_MOUNT_XIP) &&
+           !sb->s_bdev->bd_disk->fops->direct_access) {
+               sbi->s_mount_opt &= (~EXT2_MOUNT_XIP);
+               ext2_warning(sb, __FUNCTION__,
+                            "ignoring xip option - not supported by bdev");
        }
 }
 
-struct page*
-ext2_get_xip_page(struct address_space *mapping, sector_t blockno,
+struct page *
+ext2_get_xip_page(struct address_space *mapping, sector_t offset,
                   int create)
 {
        int rc;
        unsigned long data;
-       struct buffer_head tmp;
+       sector_t sector;
 
-       tmp.b_state = 0;
-       tmp.b_blocknr = 0;
-       rc = ext2_get_block(mapping->host, blockno/(PAGE_SIZE/512) , &tmp,
-                               create);
+       /* first, retrieve the sector number */
+       rc = __ext2_get_sector(mapping->host, offset, create, &sector);
        if (rc)
-               return ERR_PTR(rc);
-       if (tmp.b_blocknr == 0) {
-               /* SPARSE block */
-               BUG_ON(create);
-               return ERR_PTR(-ENODATA);
-       }
+               goto error;
 
+       /* retrieve address of the target data */
        rc = __inode_direct_access
-               (mapping->host,tmp.b_blocknr*(PAGE_SIZE/512) ,&data);
-       if (rc)
-               return ERR_PTR(rc);
+               (mapping->host, sector * (PAGE_SIZE/512), &data);
+       if (!rc)
+               return virt_to_page(data);
 
-       SetPageUptodate(virt_to_page(data));
-       return virt_to_page(data);
+ error:
+       return ERR_PTR(rc);
 }